• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.1
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• pp.154-159
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• 2008

This study proposes how to decide mean velocity which is one of the very important and efficient discharge measurement in water resources area. In order to achieve this goal, Chiu's velocity distribution equation recently developed from the probability and entropy concepts is used to establish, analyze and compare a linkage between the mean velocity obtained from the Manning's equation which is well known in the world. Besides, it becomes clear that a channel cross section also has a propensity to establish and maintain an equilibrium state that can be measured and classified by a function of entropy M, ratio of mean and maximum velocities irrespective of including sediment or varied channel slope. Therefore, The linkage to be established in this study can be used to compute the cross sectional velocity distribution with the maximum velocity.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.5
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• pp.11-17
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• 2016

In this paper, we propose a method of correcting depth image by the plane modeling and then improving the coding performance. We model a plane by using the least squares method to the horizontal and vertical directions including the target pixel, and then determine that the predicted plane is suitable from the estimate error. After that, we correct the target pixel by the plane mode. The proposed method can correct not only the depth image composed the plane but also the complex depth image. From the simulation result that measures the entropy power, which can estimate the coding performance, we can see that the coding performance by the proposed method is improved up to 80.2%.

• Annual Conference on Human and Language Technology
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• 1999.10d
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• pp.117-122
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• 1999

본 연구는 형태소 분석에 필요한 언어 지식과 품사 태깅에 필요한 확률 정보를 별도의 언어 지식 추가 없이 학습 말뭉치를 통해서 얻어내는 방법을 제안한다. 먼저 품사 부착된 학습 말뭉치로부터 형태소 사전과 결합 정보를 추출한다. 그리고 자주 발생하는 어절 및 해석상 모호성이 많은 어절에 대해서는 학습 말뭉치에서 발견된 형태소 분석 결과를 저장하여 형태소 분석에 소요되는 시간과 형태소 분석의 정확률을 높인다. 또한 미등록어의 많은 부분을 차지하는 인명, 지명, 조직명에 대해서는 정보 추출 분야에서 사용하는 고유 명사 분류법으로 해결한다. 품사 태깅을 위해서는 품사열 정보와 품사열 정보로는 해결할 수 없는 경우를 위한 어휘 정보를 학습 말뭉치에서 추출한다. 품사열 정보와 어휘 정보는 정형화 과정을 거쳐 최대 엔트로피 모델의 자질로 사용되어 품사 태깅 시스템을 위한 확률 분포를 구성한다. 본 연구에서 제안하는 방법은 학습 말뭉치를 기반으로 한다는 특성에 의해 다양한 영역에 사용하기 쉽다. 또한 어휘 정보로 품사 문맥 정보를 보완하기 때문에 품사 분류 체계와 형태소 해석 규칙에 영향을 적게 받는다는 장점을 가진다. MATEC '99 데이터 실험 결과 형태소 단위로 94%의 재현률과 93%의 정확률을 얻을 수 있었다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.6
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• pp.140-146
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• 1989

In many situations, radar targets are embedded in a clutter environment and clutter rejection is required. The clutter is unwanted radar echoes and may arise owing to reflections from ground and weather disturbances and statistical properties of the clutter vary with range and azimuth as well as time. That is, adaptive signal processing is required. In this paper, a clutter suppression algorithm based on the clutter whitening filter (WF) and doppler filter bank(DFB) is described which provides improved performance compared with conventional nonadaptive clutter suppression algorithm that is the cascaded moving target indicator (MTI) and (DFB). The clutter whitening filter algorithm is based on the Burg's maximum entropy method.

• Journal of the Korea Society of Computer and Information
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• v.10 no.2 s.34
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• pp.1-10
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• 2005

In this Paper, we propose a new block matching a1gorithm that extracts motion vectors from consecutive range data. The proposed method defines a matching metric that integrates intensity, hue, and range. Our algorithm begins matching with a small matching template. If the matching degree is not good enough, we slightly expand the size of a matching template and then repeat the matching process until our matching criterion is satisfied or the predetermined maximum size has been reached. As the iteration proceeds, we adaptively adjust weights of the matching metric by considering the importance of each feature. In the experiments, we show that our block matching approach can work as a promising solution by comparing the proposed method with previously known method in terms of performance.

• Journal of Fisheries and Marine Sciences Education
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• v.18 no.1
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• pp.19-30
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• 2006

For fishery stock assessment and optimum sustainable yield of anchovy in Korea, surplus production(SP) models and a maximum entropy(ME) model are employed in this paper. For determining appropriate models, five traditional SP models-Schaefer model, Schnute model, Walters and Hilborn model, Fox model, and Clarke, Yoshimoto and Pooley (CYP) model- are tested for effort and catch data of anchovy that occupies 7% in the total fisheries landings of Korea. Only CYP model of five SP models fits statistically significant at the 10% level. Estimated intrinsic growth rates are similar in both CYP and ME models, while environmental carrying capacity of the ME model is quite greater than that of the CYP model. In addition, the estimated maximum sustainable yield(MSY), 213,287 tons in the ME model is slightly higher than that of CYP model (198,364 tons). Biomass for MSY in the ME model, however, is calculated 651,000 tons which is considerably greater than that of the CYP model (322,881 tons). It is meaningful in that two models are compared for noting some implications about any significant difference of stock assessment and their potential strength and weakness.

• The Journal of Korean Association of Computer Education
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• v.10 no.3
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• pp.67-73
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• 2007

In this paper, we review essential constituents of a dialogue interface system and propose practical methods to implement the each constituent. The implemented system consists of a discourse manager, an intention analyzer, a named entity recognizer, a SQL query generator, and a response generator. In the progress of implementation, the intention analyzer uses a maximum entropy model based on statistics because the domain dependency of the intention analyzer is comparatively low. The others use a simple pattern matching method because they needs high domain portability. In the experiments in a schedule arrangement domain, the implemented system showed the precision of 88.1% in intention analysis and the success rate of 83,4% in SQL query generation.

• Annual Conference on Human and Language Technology
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• 2007.10a
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• pp.31-37
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• 2007

본 논문에서는 분야 시소러스의 개념과 관계를 이용하여 코아 온톨로지를 확장하는 방법을 제안한다. 분야 시소러스의 개념을 코아 온톨로지의 상위 개념으로 분류하고, 시소러스에서의 광의어(Broader Term: BT)-협의어(Narrower Term: NT) 및 광의어-관련어(Related Term: RT)들 사이의 관계는 코아 온톨로지에서 정의한 의미관계로 분류한다. 유사도와 빈도수 기반의 방법으로 개념 분류를 수행하였고, 관계 분류에서는 두 가지 방법을 적용하였는데, (i) 훈련데이터가 부족한 경우를 위하여 규칙기반 방법으로 BT-NT/RT관계를 isa와 기타 관계(non-isa관계)로 분류하고, 패턴기반 방법으로 non-isa관계를 온톨로지를 위한 의미관계로 분류한다. (ii) 훈련데이터를 충분히 가지고 있을 경우, 최대 엔트로피 모델(MEM)을 적용한 분류 방법을 사용하되, kNN방법으로 훈련데이터를 정제하였다. 본 논문에서 제안한 방법으로 시스템을 구축하였고, 실험 결과, 시스템 성능이 사람에 의한 판단 결과와 비교 가능한 수준이었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5C
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• pp.520-529
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• 2007

In this paper, we study the characteristics of parameters which are related to performance of MCTF which is a key technique for wavelet-based scalable video coding, and propose an improved MCTF method. The proposed MCTF method adopts the motion estimation of which motion vector field is distributed more uniformly using variable block sizes. By using the proposed method, the decomposition performance of temporal filter is improved, and the energy in high-frequency frames is reduced. It can help the entropy coder to generate lower bitrate. From simulation results, we verify the decomposed energy on high-frequency frame using the proposed method is reduced by 25.86% at the most in terms of variance of the high-frequency frame.

• Journal of Biomedical Engineering Research
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• v.21 no.5
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• pp.527-535
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• 2000

For a reliable patient set-up verification, better portal films are needed to track relevant features. Simulator films are compared with portal films as a reference image in radiotherapy planning. This shows some possibilities of the use of image information of simulator images for enhancement and restorations of portal images which are very poor in quality compared with the simulator images. This paper present an approach that combine an associative memory, a kind of artificial neural networks with fuzzy image enhancement technique using genetic algorithm which determines the fuzzy region of membership function by the use of maximum entropy principles. A higher portal image quality than conventional technique is achieved.